Psychotria guillauminiana is an endemic shrub of New Caledonia, restricted to Col de Mô, Vallée de la Ouano, Vallée de la Tontouta, Rivière du Humboldt and Mont Mou in the south of Grande Terre It occurs in forest or shrubland on ultramafic susbtrate at an altitudinal range 130-700 m asl. The main impact identified comes from bushfires and mining activities. Its area of occupancy (AOO) and extent of occurrence (EOO) being respectively estimated to 36 and 195 km², while the number of locations are estimated to be five: Col de Mô / Vallée de la Ouano, Vallée de la Tontouta, Mine Vulcain (SMGM), Rivière du Humboldt and Mont Mou. Psychotria guillauminiana is therefore assessed as Endangered (EN) with criteria B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v) with a continuing decline of all concerned sub-criteria.

Geographical area

Psychotria guillauminiana is an endemic shrub of New Caledonia, restricted to Col de Mô, Vallée de la Ouano, Vallée de la Tontouta, Rivière du Humboldt and Mont Mou in the south of Grande Terre

Population

It is known from five sub-populations : Col de Mô, vallée de la Ouano, Vallée de la Tontouta, Rivière du Humboldt and Mont Mou.

Habitat

It occurs in forest or shrubland on ultramafic susbtrate at an altitudinal range 130-700 m asl.

Threats

Main identified threat is linked to habitat damaging by uncontrolled bushfires and some subpopulations may be threatened by mining activities: Vulcain (SMGM). Uncontrolled bushfires sweep across New Caledonia each year, especially during the dry season (an average of 20,000 ha of land is burnt each year, with dramatic peaks of 70,000 ha). Lowest parts of ultramafic areas are particularly exposed to such risk.

Conservation

Psychotria guillauminiana is unprotected by legislation and it does not occur in any protected area. It is recommended to inform the DSCGR (emergency services) on the presence of the species in the concerned areas. This species would benefit from ex-situ and in-situ emergency conservation actions. It is proposed to ensure the follow-up of known sub-populations, to preserve a viable population on delimited perimeters on the mining area. It would be moreover advised to realize multiplication tests in order to assist future planting operations.

Bibliography

Endemia.nc 2016. Faune et Flore de Nouvelle-Calédonie.

Barrabé L, Maggia L, Pillon Y, Rigault F, Mouly A, Davis AP, Buerki S 2014. New Caledonian lineages of Psychotria (Rubiaceae) reveal different evolutionary histories and the largest documented plant radiation for the archipelago. Molecular Phylogenetics and Evolution(71) , p.15-35.

Morat, P.; Jaffré, T.; Tronchet, F.; Munzinger, J.; Pillon, Y.; Veillon, J.-M. and Chalopin, M. 2012. Le référentiel taxonomique Florical et les caractéristiques de la flore vasculaire indigène de la Nouvelle-Calédonie [The taxonomic database « FLORICAL » and characteristics of the indigenous flora of New Caledonia]. Adansonia sér 3(34) , p.177-219.

Barrabé L. 2013. Systématique et Evolution du genre Psychotria (Rubiaceæ) en Nouvelle-Calédonie.

Experts

Assessor(s): Barrabé, L., Amice, R., Bruy, D., Cazé, H., Dumontet, V., Fleurot, D., Garnier, D., Gâteblé, G., Hequet, V., Maura, J., McCoy, S., Suprin, B., Vandrot, H., Veillon, J.

Reviewer(s): Tanguy, V., Lannuzel, G.

Facilitator(s): Tanguy, V., Ramon, L., Maura, J., Warimavute, G.